The specific aim of this project is to determine if the yields of DSBs relative to DSBs are markedly different for alpha-particles and gamma-rays, the ratio being much lower for the higher LET radiation. There is also a characteristic dependence of the yield ratio on scavenger concentration for the low LET radiation but no apparent dependence for the alpha-particles. Thus this system would be useful in determining the effectiveness of soft neutrons in producing these types of damage.